Is neuroimaging overused when patients with seizures present to the ED? A new study suggests so.

These investigators noted that EDs often use CT scans in seizure patients. If the seizure is new onset, imaging changes care for an estimated 9-17% of cases. However, investigators noted that data are not as clear regarding how often care is altered following imaging in the ED for adults with known seizure disorders.

To determine that, investigators reviewed 822 consecutive ED visits for non-index seizures at the Oregon Health & Science University and the VA Portland Health Care System. The authors collected details of the clinical presentation, whether anyone obtained neuroimaging, neuroimaging results, and results of prior neuroimaging. Concurrently, researchers explored whether ED neuroimaging led to a significant change in patient management, defined as the “yield.”

Overall, researchers determined that 78% of ED seizure visits were for non-index seizures, with neuroimaging results available for 46% of the visits by patients with known seizure disorders.

Results indicate that 11 imaging studies led to a meaningful change in patient management, which dropped to eight after excluding false-positive scans. Factors associated with an increased yield of ED neuroimaging were acute head trauma, prolonged alteration of consciousness, and a focal neurologic examination at presentation. The actual yield in cases without those three characteristics was essentially zero.

The researchers emphasized that their results suggest a more conservative use of ED neuroimaging for non-index seizures, based on clinical factors at the time of presentation.